Among the moving messages from mourners, a letter is written in French with a yellow marker pen on white paper.

"They thought they could silence your voice forever," it reads. "But your voice has risen to enlighten. We are proud of you. We will follow your path. Sleep with that knowledge."

Belaid, killed on February 6 by men shooting at him from motorcycles, had warned his family there might be an attempt on his life, having received death threats on his phone.

But even he could not have possibly guessed the murder would have happened in daylight just metres from his home. What strikes you about the crime's location is how built up this middle-class area is, surrounded by apartment blocks.

As I look up I observe a shadow pass a window. I imagine it's someone conducting the investigation, which is being led by Tunisia's judiciary, who must have spoken to several witnesses that morning.

Ali Larayedh, the interior minister, announced the first arrests in the case on Thursday. "The investigation has not led yet to identify the killer, those behind the murder and its motives," he said in Tunis.

Power outage

It was a journalist who discovered that the power in the area where Belaid was killed had gone off sometime during the night.

It's still unclear whether the outage was related to what happened, but the news certainly aroused suspicions.

Ennahdha has called what happened to Belaid "a hateful crime that was aimed at aborting the revolution and derailing the transition in our country".

However, members of Belaid's family have pointed their fingers at the ruling party, holding them politically accountable.

I have watched this party grow from an initial group of exiled men and former political prisoners returning to their homeland, into an organised and victorious party in the election for a constituent assembly.

Youssef Cherif, a Tunisian blogger I first met in January 2011, doesn't blame the government for Belaid's assassination.

"Even during their violent phase in the 1980s they didn't resort to such targeted killings," he said.

"There are also enough moderates inside the party and such killing, would alienate them more."

'Climate of hate'

Cherif added that members of Ennahdha had made attacks on Belaid in the media.

"This has contributed to a climate of hate towards Belaid in a country were smaller radical groups are spreading," he said.

Cherif says that ministers from Ennahdha "have tolerated violent movements such as the League for the Protection of the Revolution, and the jihadi Salafists, and weren't quick enough to arrest or investigate those accused of arms smuggling.

"It is therefore their negligence which facilitated the murder, and they have a moral responsibility".

Hama Hamami, spokesman for the Popular Front, which was aligned to Belaid's United Democratic Patriots, has also received death threats.

He now has protection from the president and leaves his home in a 4WD vehicle with four bodyguards in tow.

He thinks the government has "left open a climate which is favourable to violence, and aggression, which has made it easier to assassinate people like Shokri Belaid".

The climate that Hamami is talking about includes a series of incidents and attacks on politicians and artists over the last year.

Concerted 'media campaign'

One of the most recent attacks, earlier in February, was on a meeting of Belaid's party in El Kef. Witnesses blamed Salafists and Ennahada supporters.

Ennahdha says it is blamed as part of a concerted "media campaign against it and an attempt to mislead public opinion".

I have been reporting from Tunisia for the last two years, and what I find frustrating is the growing tendency to simplify what is happening in Tunisia as a struggle between secularists and Islamists.

Hamami agrees.

He says this is more of a struggle between "democracy and oppression".

There are certainly those in Tunisia and abroad who perhaps don't want the revolution to succeed.

Having seen first-hand the joy of the revolution, and then the realities of transition, most Tunisians want reform and democracy.

In the coming months we will know whether Tunisians are able to overcome the death of Shokri Belaid, or if his assassination divides the country even further.